Chemical bath deposited (Cd0.85-Zn0.15)S nanocrystalline film: Influence of capping agent on various characterizations

Abstract

The (Cd 0.85 -Zn 0.15 )S ternary alloy film was deposited on FTO coated glass substrate by chemical bath deposition (CBD) technique using Mercaptoethanol (MEL), Thiophenol (TP), Polyvinylpyrrolidone (PVP) and Thioglycerol (TG) as capping agents. In order to classify the crystalline behavior of the deposited films, X-ray diffraction (XRD) studies were performed. Broad and narrow peaks were identified for the uncapped and capped films, respectively. Confirmation of hexagonal crystal structure was demonstrated and the highest peak was observed along the (002) orientation. The surface morphology was studied using scanning electron microscopy (SEM). Cabbage-like morphology was observed for uncapped (Cd 0.85 -Zn 0.15 )S film whereas honey comb, spherical like structure was observed for the capped films. In optical studies, absorption spectra of capped films were observed to be shifted to the lower wavelength side in comparison to the uncapped film. Energy band-gap values of capped films were found to be greater than that of the uncapped film. The variation in optical constants was also studied using various parameters. Photoluminescence spectra werealso recorded and the variation in uncapped and capped films was compared. • The (Cd 0.85 -Zn 0.15 )S ternary alloy is deposited on FTO substrate by CBD technique. • Structural and optical properties are compared for MEL, TP, PVP and TG capped film. • Sharp and narrow peaks are observed in structural analysis. • Particle sizes are observed to be reduced in presence of capping agents. • Band-gap value for capped (Cd 0.85 -Zn 0.15 )S film varies between 2.64 eV and 2.80 eV.